package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * @description:
 * @author: ajie
 * @date: 2024/2/20 15:02:15
 * @version: 1.0
 */
@Service
public class IFollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    StringRedisTemplate stringRedisTemplate;
    @Resource
    IUserService userService;

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //获取当前用户
        UserDTO user = UserHolder.getUser();
        if (user == null){
            //当前用户未登录
            return Result.fail("当前用户未登录");
        }
        Long userId = user.getId();
        String key = "follows:"+userId;
        //判断到底是关注还是取关
        if (isFollow){
            //关注，新增数据
            Follow follow = new Follow();
            follow.setFollowUserId(followUserId);
            follow.setUserId(userId);
            boolean isSuccess = save(follow);
            if (isSuccess){
                //把关注用户的id，放入redis集合 sadd userId followUserId
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        }else {
            //取关，删除 delete from tb_follow where user_id = ? and follow_user_id ?
            boolean isSuccess = remove(new QueryWrapper<Follow>().eq("user_id", userId).eq("follow_user_id", followUserId));
            if (isSuccess) {
                //把关注用户的id从redis中移除
                stringRedisTemplate.opsForSet().remove(key,followUserId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        //获取当前用户
        UserDTO user = UserHolder.getUser();
        if (user == null){
            //当前用户未登录
            return Result.fail("当前用户未登录");
        }
        Long userId = user.getId();
        //查询是否关注 select * from tb_follow where user_id = ? and follow_user_id = ?
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        //判断
        return Result.ok(count > 0);
    }

    @Override
    public Result followCommons(Long id) {
        //获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key1 = "follows:"+userId;
        //求交集
        String key2 = "follows:"+id;
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key1, key2);
        if (intersect == null || intersect.isEmpty()){
            //无交集
            return Result.ok(Collections.emptyList());
        }
        //解析id集合
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //查询用户
        List<UserDTO> userDTOS = userService.listByIds(ids).stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());

        return Result.ok(userDTOS);
    }
}
